I am convinced on the basis of science and personal experience that there is an afterlife.
Regarding science, I published my views in the Quantum Mind 2003 conference. The paper may be found at http://www.dhushara.com/pdf/ruquist.pdf.
Briefly, I believe that consciousness resides in media that is quantum coherent and totally entangled, like in a superfluid or superconductor. Of course, there needs to be some intelligence as well. I do not expect a superconductor to be conscious.
A component of Dark Matter, in my cosmology, is an axion condensate, which is a superfluid, and this superfluid permeates our galaxy, our planet and even our brains. For most of us, our physical consciousness is reflected in this medium. The medium may be the missing integrating factor needed for conscious thought. But the visible part of our consciousness, our imagination, exists in neurons. However, there is some data suggesting that our consciousness can leave our body. The Astronaut Mitchell published experiments in the Proc of the IEEE that verifies this possibility.
I think that the consciousness that can leave one's body exists in the superfluid component of Dark Matter. But actually, the very fact that consciousness can exist outside the body is sufficient evidence for an afterlife.
On a personal level, I have a friend that can channel. (See www.letusreason.org/NAM13.htm for details) The dead fellow channeled for me revealed information that neither my friend or I could know, that turned out to be true. I've discussed this often on this forum. So I will not go into detail now. But it is clear to me that the information came from somewhere else, and the spirit being channeled claimed to be a recently dead Irishman. I had no reason for disbelief.
On the other hand, I remain scared to death.